The 368 or so recognized species of shark are a group of carnivorous fish with cartilaginous
skeletons which are placed in the class Chondrichthyes with the rays, skates, and chimaeras. They
have streamlined bodies with between 5 and 7 gill slits, usually along their sides, but sometimes
on the side of the head (with the first modified slit behind the eye called a
"spiracle"). The skin is covered by denticles to protect it from
parasites and there are multiple rows of replaceable teeth in the mouth which advance to replace any brocken teeth.
These fish are an ancient group which first appeared in the earth's oceans between 400 and 350 million years ago amd most of the species which are recognised today have changed little since the Jurassic period (about 135 to 195 million years ago).
Sharks were usually referred to as "sea-dogs" until the word "shark began to be used in the late 1560s to refer to the large species of the Caribbean Sea. Gradually the word came to be used for all members of the group, although their smaller relatives are still commonly known as "dogfish".
|
The word "shark" may have its origins in the Mayan word for the animals, "xoc" (pronounced "shock" or "shawk").
|
The sharks first appeared between 350 and 400 million years ago during the Devonian period.
the Sharp-Nosed or Seven-Gilled Shark (Scoliodon terrae-novae), usually found in more southerly waters, was recorded off the Cornish coast in 1984. As with many marine sightings of this nature, this may be indicative of the shark extending its range northwards as the result of climatic change or perhaps being swept from itsa normal range by ocean currents.
Between about 1.5 and 25 million years ago, during the Miocene and Pliocene epochs, Carcharadon megalodon which exceeded 12.5 metres was the largest shark that ever lived - its jaws were large enough to swallow a car and equiped with teeth up to 17 cm long. "Megalodon" means "big tooth". Only its fossilized teeth and a few
fossilized vertebrae that have been found and some scientists have estimated its length as much as between 15 and 31 metres (45-over 100 feet).
About twenty one species of sharks have been recorded in British coastal waters with the small Scyliorhinus canicula, the Lesser Spotted Dogfish, is the most numerous;-
| SCIENTIFIC NAME | COMMON NAME | FAMILY |
| Alopias superciliosus | | |
| Alopius vulpinus | | |
| Cetorhinus maximus | Basking Shark | Cetorhinidae |
| A plankton feeder, this is the largest shark to frequent British waters |
| Chlamydoselachus anguineus | | |
| Dalatias licha | | |
| Echinorhinus brucus | | |
| Etmopterus spinax | | |
| Galeorhinus galeus | | |
| Galeus melastomus | | |
| Heptranehias perlo | | |
| Hexanchus griseus | Six-Gilled Shark | Hexanchidae |
| A deep water species, the juveniles of which are encountered in waters near the coast |
| Isurus oxyrinchus | | |
| Lamna nasus | | |
| Mustelus asterias | | |
| Mustelus mustelus | | |
| Prionace glauca | | |
| Scyliorhinus canicula | Lesser Spotted Dogfish | |
| Rarely exceeding a metre in length, this is the commonest shark species in British coastal waters. Its egg case is known as a "Mermaid's purse" |
| Scyliorhinus stellaris | | |
| Somnulosus microcephalus | | |
| Sphyrna zygaena | | |
| Squalus acanthias | | |
| Squatina squatina | | |
The largest shark found off the British Isles is the Basking Shark, Cetorhinus maximus. This huge plankton feeder can grow to nine metres (eighteen feet) in length and is sometimes seen in very shallow water.
The Shark Trust promotes the study, management and conservation of sharks, skates and rays. The Shark Trust is the UK member of the European Elasmobranch Association. As such, it collaborates with other national member bodies to achieve their aims in British, European and international waters. The Trust aims to join forces with other groups concerned with shark, skate and ray conservation issues. These include commercial fisherman, recreational sea anglers, divers, yachtsmen, and all those who want to ensure the future survival of these fascinating but threatened animals.
click here for The Shark Trust's website
|
| | | Links to Other Pages on This Site
|
| |
| | |
|
| | | Links to Other Sites
|
| |
| | |
|
| | | Links to Other Pages on this Site
|
| |
| | |
Recommend a Book for this Page
Hits on this page since December 6th| Jan | | | | | Feb | | | | | Mar | | | | | Apr | | | | | May | | | | | Jun | | | | | Jul | | | | | Aug | | |  | | Sep | | | | | Oct | | | | | Nov | | | | | Dec | | |  |
| current year: | | previous year: |
Warning: mysql_numrows(): supplied argument is not a valid MySQL result resource in /customers/swuklink.com/swuklink.com/httpd.www/BAAAGCNB.php on line 637
Warning: mysql_numrows(): supplied argument is not a valid MySQL result resource in /customers/swuklink.com/swuklink.com/httpd.www/BAAAGCNB.php on line 638
members online now
No messages posted on this page Only Members of the Site can post messages in this section. Signing in is easy from our Home Page. DISCLAIMER: Whilst we endeavour to ensure the content of this site is correct, we cannot undertake that information you find here, is, or will remain accurate and complete. We do not warrant that any information contained on this site is fit for any purpose. If you wish to place reliance on any such information you must check its accuracy by some other means before doing so. MEMBERS get aditional features on our pages and will soon be able to interact with the site and add their views and informastion. Sign up, from the Home-Page, is simple and involves typing in your email address and a password of your choice. If you are in any way connected with any location or interested in the subject mentioned on this page and have an hour or two a month to spare, we would welcome you as a local moderator - please email the webmaster by CLICKING HERE. Privacy Policy
|
| 
